Collective Minds Radiology Backend Engineer interview questions

Don't apply for this company. I put >12 hours into the interview process, was given an offer which I accepted, only for it to be withdrawn a week later with absolutely no explanation on why. I had already started the visa process and started to prepare for moving to a new country, something that requires a lot of time and energy. Yet despite all this, all I got was a call from the HR person who knew nothing about the situation, telling me the offer had been withdrawn. My attempts to request clarification from the CTO were completely ignored. I was treated incredibly badly. If that is the way that they treat people in their organisation, I can only hope that I missed a bullet. It was very cruel. The process was a fairly average software engineering interview experience: screening -> high level tech discussion -> tech assignment -> CTO interview.